Influence of Platinum Bottom Electrodes on the Piezoelectric Performance of PZT Thin Films Hot Sputtered in a High Volume Production Tool

2012 ◽  
Vol 1397 ◽  
Author(s):  
Dirk Kaden ◽  
Hans-Joachim Quenzer ◽  
Martin Kratzer ◽  
Lorenzo Castaldi ◽  
Bernhard Wagner ◽  
...  
Keyword(s):  
Thin Films ◽  
Volume Fraction ◽  
Perovskite Phase ◽  
Annealing Treatment ◽  
High Volume ◽  
Deposition Process ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
High Volume Production ◽  
Volume Production

ABSTRACTIn this work high quality ferroelectric PZT films have been prepared in-situ by hot RF magnetron sputtering. 200 mm wafer were coated with PZT films of 1 μm and 2 μm thickness at sputter rates of 45 nm/min in a high volume production sputtering tool. The films were grown on oxidized Si substrates prepared either with sputtered Ti/TiO2/Pt, sputtered Ti/TiO2/Pt/TiO2 or evaporated Ti/Pt bottom electrodes at substrate holder temperatures in the range from 550 °C to 700 °C. At these temperatures, the material nucleates in the requisite piezoelectric perovskite phase without need of an additional post annealing treatment.The films were investigated with respect to their chemical composition and their crystallographic, piezoelectric and dielectric properties. At an intermediate chuck temperature of 600 °C the PZT thin films were characterized by a minimum volume fraction of secondary nonpiezoelectric phases. A Zr/(Zr+Ti) ratio of 0.53 has been achieved matching the morphotropic phase boundary. By improving the deposition process and poling procedure, a notable high e31,f coefficient of -17.3 C/m2 has been obtained. The corresponding longitudinal piezoelectric constant was determined to have an effective longitudinal piezoelectric coefficient d33,f of 160 pm/V.

Preparation of pzt thin films on Pt/Ti/SiO2 and Pt/SiO2 Substrates by ECR Plasma Enhanced DC Magnetron Multi-target Reactive Sputtering

1996 ◽  
Vol 441 ◽  
Author(s):  
Sung-Tae Kim ◽  
Hyun-Ho Kim ◽  
Moon-Yong Lee ◽  
Won-Jong Lee
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Electron Cyclotron Resonance ◽  
Perovskite Phase ◽  
Early Stage ◽  
Reactive Sputtering ◽  
Deposition Process ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Ecr Plasma

AbstractPerovskite-phase lead zirconate titanate (PZT) thin films were fabricated at 4751C by the electron cyclotron resonance (ECR) plasma enhanced DC magnetron multi-target reactive sputtering method on Pt/Ti/SiO2/Si and Pt/SiO2/Si substrates. Stoichiometric perovskite PZT films were readily obtained on Pt/Ti/SiO2/Si substrates because Ti atoms which were out-diffused to the Pt surface facilitated Pb incorporation by forming lead titanate at the early stage of deposition process. Activation of oxygen by ECR plasma facilitated the oxidation reaction and Pb incorporation into the film. Thus perovskite-phase PZT can be obtained on the Pt/SiO2/Si substrate.

A Study on the Selective Nucleations for Formation of Large Single Grains in PZT Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
Jang-Sik Lee ◽  
Eung-Chul Park ◽  
Jung-Ho Park ◽  
Byung-Il Lee ◽  
Seung-Ki Joo
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Perovskite Phase ◽  
Breakdown Field ◽  
Pzt Thin Films ◽  
Random Nucleation ◽  
Saturation Polarization ◽  
Pt Electrodes ◽  
Pzt Films ◽  
Pt Films

AbstractSelective nucleation and lateral growing method have been developed for high quality ferroelectric PZT(65/35) thin films using perovskite-phase PZT island seed. The PZT films on PZT seed island were transformed into the perovskite phase at temperatures as low as 540°C, which is 150°C lower than compared to that of PZT thin films deposited on Pt films. The temperature difference enables lateral growth without undesirable random nucleation. Maximum grain sizes of the perovskite-phase PZT films were determined by the annealing temperature. The PZT thin films show a leakage current density of 8×10−8 A/cm2, breakdown field of 1240 kV/cm, saturation polarization of 42 μC/cm2, and remanent polarization of 30 μC/cm2, whose values were maintained up to 2×1011 cycles. In this study, we show that when there was no grain boundary in the area measured, degradation such as fatigue and retention was not observed even with Pt electrodes. So the main source of degradation is the grain boundary in the PZT thin films.

scholarly journals Structural Characterization of SiF4, SiH4 and H2 Hot-Wire-Grown Microcrystalline Silicon Thin Films with Large Grains

2001 ◽  
Vol 664 ◽  
Author(s):  
J. J. Gutierrez ◽  
C. E. Inglefield ◽  
C. P. An ◽  
M. C. DeLong ◽  
P. C. Taylor ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Vapor Deposition ◽  
Volume Fraction ◽  
Annealing Treatment ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Hot Wire ◽  
Microcrystalline Silicon ◽  
Crystal Volume

ABSTRACTIn this paper, we present a comprehensive study of microcrystalline silicon thin film samples deposited by a novel growth process intended to maximize their grain size and crystal volume fraction. Using Atomic Force Microscopy, Raman spectroscopy, and x ray diffraction the structural properties of these samples were characterized qualitatively and quantitatively. Samples were grown using a Hot-Wire Chemical Vapor Deposition process with or without a post-growth hot-wire annealing treatment. During Hot-Wire Chemical Vapor Deposition, SiF4 is used along with SiH4 and H2 to grow the thin films. After growth, some samples received an annealing treatment with only SiF4 and H2 present. These samples were compared to each other in order to determine the deposition conditions that maximize grain size. Large microcrystalline grains were found to be aggregates of much smaller crystallites whose size is nearly independent of deposition type and post-annealing treatment. Thin films deposited using the deposition process with SiF4 partial flow rate of 2 sccm and post-growth annealing treatment had the largest aggregate grains ∼.5 µm and relatively high crystal volume fraction.

Issues in the Flexible Integration of Sputter-Deposited PZT Thin Films with Polysilicon and Ti/Pt Electrode Layers for Use as Sensors and Actuators in Microelectromechanical Systems (MEMS)

2000 ◽  
Vol 657 ◽  
Author(s):  
C.F. Knollenberg ◽  
T.D. Sands ◽  
A.S. Nickles ◽  
R.M. White
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Microelectromechanical Systems ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Pt Electrode ◽  
Electrode Layer ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
Sputter Deposited

ABSTRACTSputter-deposited piezoelectric lead zirconate titanate (PZT) thin films with Ti/Pt and polysilicon electrode layers are being investigated for use in Microelectromechanical Systems (MEMS). Existing research shows the nucleation of the perovskite phase of the PZT is linked to the lattice spacing of the underlying Pt electrode and/or seed layers, and is key in obtaining PZT layers with good piezoelectric/ferroelectric properties. Our research with piezoelectric PZT films on Ti/Pt electrode layers aims at employing these films to generate and receive acoustic waves in flexural plate wave devices (FPWs). Our experiments indicate the formation of a random polycrystalline perovskite phase is linked to the emergence of oriented <100> Pt grains within the dominant <111>-oriented crystal structure during rapid thermal annealing in an oxygen environment. Pt films annealed in nitrogen, in contrast, retained their <111> preferential orientation without the formation of Pt <100> grains. PZT films deposited on these electrodes and annealed in nitrogen were strongly oriented in the <111> direction, but exhibited lossy ferroelectric behavior and were prone to delamination. We are also investigating the feasibility of using doped polysilicon electrode layers with PZT thin films. The multiple layers used with the Pt electrode (Pt, Ti, and SiO2 adhesion layer) have significant interactions with one another, and replacing these layers with a single electrode layer should alleviate these complications. A low-temperature PZT deposition process (300°C) and short annealing cycles (30 sec.), coupled with a TiO2 barrier/seed layer should prevent interdiffusion and reactions between the polysilicon and PZT layers. Our experiments show that PZT films deposited and annealed on doped polysilicon layers develop a random polycrystalline perovskite phase, but are subject to tensile cracking. The use of polysilicon as an electrode layer should also facilitate the integration of piezoelectric PZT layers with polysilicon surface micromachined structures using SiGe sacrificial layers.

Laser-Assisted Low Temperature Processing of PZT Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
Yongfei Zhu ◽  
Jinsong Zhu ◽  
Y. J. Song ◽  
S. B. Desu
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
Laser Annealing ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Processing Temperature ◽  
Pzt Thin Films ◽  
Step Process ◽  
Pzt Films ◽  
One Step

ABSTRACTA novel method for lowering processing temperature of ferroelectric Pb(Zr1−xTix)O3 (PZT) thin films was developed utilizing a laser-assisted two-step process. In the first step, perovskite phase was initiated in the PZT films by subjecting the films to a fornace anneal at low temperatures in the range of 470 °C to 550 °C depending on the Zr/Ti ratio. Later, the films were laser-annealed (using krF excimer laser) at room temperature to grow the perovskite phase, and to improve microstructure and ferroelectric properties. It was found that this two-step process was very effective in producing excellent quality ferroelectric PZT films at low temperatures. It should be noted that although laser annealing of amorphous and/or pyrochlore films directly (one-step process) produces perovskite phase, the ferroelectric properties of these films, irrespective of the composition, were rather unattractive. Some possible reasons for the ineffectiveness of the one-step process were discussed.

Pzt Thin Films on a Lead Titanate Interlayer Prepared by rf Magnetron Sputering

1993 ◽  
Vol 310 ◽  
Author(s):  
P. H. Ansari ◽  
A. Safari
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Lead Titanate ◽  
Silicon Oxide ◽  
Perovskite Phase ◽  
Dissipation Factor ◽  
Lead Zirconate ◽  
Si Substrate ◽  
Pzt Thin Films ◽  
Pzt Films

AbstractFerroelectric lead zirconate titanate (PZT) films with a composition near the morphotropic phase boundary have been deposited by if magnetron sputtering on a Si substrate coated with silicon oxide, titanium, and platinum (Si/SiO2/Ti/Pt). Substrate temperature and oxygen partial pressure were changed during deposition to prepare films with controlled stoichiometry and perovskite structure. The effects of lead titanate (PT) as a buffer layer were investigated. Thin films of PT/PZT have a dielectric constant of 800 with a dissipation factor of 0.04 at 1 kHz. The remnant polarization of 8μC/cm2 and the coercive field of 50 kV/cm were measured. The effect of processing on the formation of perovskite phase and the electrical properties will be discussed.

Large Area PbZr1−xTixO3 (PZT) Thin Films Deposited by MOCVD Processes

1997 ◽  
Vol 493 ◽  
Author(s):  
Tingkai Li ◽  
Elliot Hartford ◽  
Pete Zawadzki ◽  
Richard A. Stall
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Process Conditions ◽  
Large Area ◽  
Homogeneous Microstructure ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Pt Electrodes ◽  
Pzt Films ◽  
Ray Patterns

ABSTRACTAn advanced oxide MOCVD tool and processes have been developed to deposit large area PbZr1−xTixO3 (PZT) thin films on 6” Si and Pt/Ti/SiO2/Si substrates. The experimental results show the advanced oxide MOCVD tool can achieve the growth of PZT thin films with thickness uniformity of 2% and composition uniformity better that 3% on both 6” Si and Pt/Ti/SiO,/Si wafers at high deposition rates. X-ray patterns showed a single PZT perovskite phase, and AFM showed homogeneous microstructure and low surface roughness. Typically, 300 nm thick PZT films with a grain size about 0.3 μm have Pr greater than 20 - 30 μC/cm2 at 5V, a dielectric constant around 1000, low coercive field (Ec 50 - 70 kV/cm), and fatigue rate (the normalized polarization is about 0.6 after 1010 cycles at 5 V), and leakage current of 2 - 6×lO−7 A/cm2 at 150 kV/cm and room temperature on Pt electrodes. In addition, the effects of reactor design and process conditions on the thickness and composition uniformity, as well as the m i ero structure and properties were also investigated.

Effect of Pb Excess Content on Microstructure and Electrical Properties of Sol Gel Derived PZT Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
Zhan-jie Wang ◽  
Ryutaro Maeda ◽  
Kaoru Kikuchi
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Pzt Thin Films ◽  
Starting Solution ◽  
Pzt Films

AbstractLead zirconate titanate (PZT) thin films were fabricated by a three-step heat-treatment process which involves the addition of -10, 0 and 10 mol% excess Pb to the starting solution and spin coating onto Pt/Ti/SiO2/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The microstructure and composition of the films were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA), respectively. The well-crystallized perovskite phase and the (100) preferred orientation were obtained by adding 10% excess Pb to the starting solution. It was found that PZT films to which 10% excess Pb was added had better electric properties. The remanent polarization and the coercive field of this film were 34.8 μC/cm2 and 41.7 kV/cm, while the dielectric constant and loss values measured at 1 kHz were approximately 1600 and 0.04, respectively. Dielectric and ferroelectric properties were correlated to the microstructure of the films.

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